A further increase in the demand for a lithium ion battery that is compact and lightweight, has a high energy density, and is capable of repeatedly charging and discharging is expected even in view of environmental concerns. The lithium ion battery has high energy density and thus is used in the fields of a cellular phone, a notebook-sized personal computer, or the like, however, along with the expansion or development of the use, further improvement of the performance, such as reduction of the resistance, increase of the capacity, and the like is required.
An electrode for a lithium ion battery can be obtained as an electrode sheet. For example, Patent Literature 1 discloses a powder rolling apparatus in which a powder supplied between rolls of a pair of rolls for press is continuously compression-molded on a current collector by the pair of rolls for press to obtain an electrode sheet. Further, Patent Literature 2 discloses that an electrified electrode material is stuck onto a current collector, and the current collector and the powder are adhered to each other by pressurizing with a pair of heating rolls to obtain an electrode sheet.